The Kremlin on Monday said it “deeply regrets” U.S. airstrikes on Iran’s nuclear facilities over the weekend, adding that it had not been informed in advance and expressing support for Tehran.

Russian President Vladimir Putin called the strikes an “unprovoked aggression that has no justification” in his first public remarks on the incident, delivered during talks with Iranian Foreign Minister Abbas Araghchi.

“We, of course, condemn the growing number of participants in this conflict and the renewed escalation of tensions in the region, and we express deep regret in this regard,” Kremlin spokesman Dmitry Peskov told reporters.

Neither Putin nor Peskov explicitly named the United States in their comments.

Peskov referred to the Russian Foreign Ministry’s earlier statement on Sunday, which strongly condemned the strikes as “irresponsible” and a “gross violation of international law” that could destabilize both regional and global security.